Compliance record
Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.
| Violation | Type | Status | Period |
|---|---|---|---|
| MCL | Health-based | Resolved | 2008-09-01 → 2008-09-30 |
| MCL | Health-based | Resolved | 2002-06-01 → 2002-06-30 |
| MCL | Health-based | Resolved | 2002-06-01 → 2002-06-30 |
| MCL | Health-based | Resolved | 2001-05-01 → 2001-05-31 |
| MCL | Health-based | Resolved | 2001-05-01 → 2001-05-31 |
| MCL | Health-based | Resolved | 1998-09-01 → 1998-09-30 |
| MCL | Health-based | Resolved | 1998-09-01 → 1998-09-30 |
| MR | Monitoring | Unaddressed | 2025-10-01 |
| MR | Monitoring | Unaddressed | 2025-10-01 |
| RPT | Monitoring | Unaddressed | 2025-07-02 |
Other contaminants detected
| Contaminant | Level vs EPA limit | Detection rate | Source | Period |
|---|---|---|---|---|
| Nitrate | 1800 µg/L 18% of the EPA limit 10000 µg/L | 16/16 | SYR4 | 2012–2019 |
| Copper | 72 µg/L 5.5% of the EPA limit 1300 µg/L | 15/15 | SYR4 | 2013–2019 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L | 8/8 | LCR | 2022 |
| Lead | 1.1 µg/L 7.3% of the EPA limit 15 µg/L | 2/15 | SYR4 | 2013–2019 |
| Arsenic | 5.3 µg/L 53% of the EPA limit 10 µg/L | 1/1 | SYR4 | 2013 |
| Barium | 26 µg/L 1.3% of the EPA limit 2000 µg/L | 1/1 | SYR4 | 2013 |
| Bromoform | 0.5000 µg/L No EPA limit set | 1/1 | SYR4 | 2019 |
| Chromium | 2.8 µg/L 2.8% of the EPA limit 100 µg/L | 1/1 | SYR4 | 2013 |
| Fluoride | 360 µg/L 9% of the EPA limit 4000 µg/L | 1/1 | SYR4 | 2013 |
| Nitrate-Nitrite | 1800 µg/L 18% of the EPA limit 10000 µg/L | 1/1 | SYR4 | 2013 |
| TTHM | 0.5000 µg/L 0.6% of the EPA limit 80 µg/L | 1/4 | SYR4 | 2015–2019 |
69 contaminants tested, none detected
Utility contact
Frequently asked questions about Sierrita Mountain Water Coop
Is Sierrita Mountain Water Coop tap water safe to drink?
EPA monitoring detected 11 contaminants in Sierrita Mountain Water Coop's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.
What contaminants were detected in Sierrita Mountain Water Coop's water?
EPA monitoring detected Nitrate, Copper, Lead, Lead, Arsenic, and others. The full list with the level and data source for each is above.
How many people does Sierrita Mountain Water Coop serve?
Sierrita Mountain Water Coop reports serving 258 people in Arizona, per its EPA record.
Has Sierrita Mountain Water Coop had any water quality violations?
The EPA has 214 violations on file for Sierrita Mountain Water Coop, of which 7 are health-based (a contaminant limit or required treatment was breached) and 3 remain open. The rest are monitoring or reporting failures.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.